Move type operations to another structure

Every type has free, print, check_constraints, ber_decoder, der_encoder,
xer_decoder, xer_encoder, uper_decoder, uper_encoder and outmost_tag
operations. We move them out to a separate structure asn_TYPE_operation_t.

Combined with previous logic simplification, these operations are based
on ASN.1 basic types, constructed types and string types. So we can
reduce the space occupied by asn_TYPE_descriptor_t variables.
diff --git a/tests/tests-c-compiler/check-src/check-126.-gen-PER.c b/tests/tests-c-compiler/check-src/check-126.-gen-PER.c
index 5b62087..9c08827 100644
--- a/tests/tests-c-compiler/check-src/check-126.-gen-PER.c
+++ b/tests/tests-c-compiler/check-src/check-126.-gen-PER.c
@@ -110,7 +110,7 @@
 			" chunks %zd\n",
 			size, fname, how==AS_PER?"PER":"XER", csize);
 
-		if(st) asn_DEF_PDU.free_struct(&asn_DEF_PDU, st, 0);
+		if(st) ASN_STRUCT_FREE(asn_DEF_PDU, st);
 		st = 0;
 
 		do {
@@ -308,7 +308,7 @@
 	else
 		assert(xer_encoding_equal((char *)fbuf, size, (char *)buf, buf_offset));
 
-	asn_DEF_PDU.free_struct(&asn_DEF_PDU, st, 0);
+	ASN_STRUCT_FREE(asn_DEF_PDU, st);
 }
 
 /*